The present invention relates to thin-film processing systems for processing semiconductor wafers and other substrates by exposure to the effects of a process energy sources. More particularly, the present invention relates to a shutter assembly for use in a thin-film processing system that is shaped to provide improved material deposition uniformity.
Thin-film processing systems are used to form thin multi-layered stacks of material on semiconductor substrates. The multi-layered stacks are generally used to form various electronic signal processing and data storing devices. For instance, semiconductor integrated circuit (IC) applications often include multi-layer interconnect structures comprised of multiple layers of glue/diffusion barrier, interconnect metal, and anti-reflection coating film. Another application that uses multi-layer material structures is magnetic data storage thin-film head devices, such as giant magnetoresistive (GMR) thin-film heads and magnetic random access memory (MRAM) spin-valve tunnel junction devices.
Thin-film processing systems generally include a processing chamber that encloses a substrate support, on which a semiconductor substrate is placed, and a process energy source. Exposure of the substrate to the process energy source results in the formation of a layer of material on the substrate.
In order to meet the never-ending demands for higher disc drive storage capacities, thin-film processing systems must be capable of depositing extremely thin layers of material to form the components of, for example, GMR heads. Additionally, the uniformity of each layer becomes a critical factor in multi-layered structures where the thickness errors are compounded. Therefore, it is desirable that the entire substrate be exposed to the process energy source for the same processing time to promote a uniform deposition of material on the substrate.
The exposure of the substrate to the process energy source is controlled by a shutter assembly. Typical shutter assemblies include a shield member and a circular shutter opening that is rotated about a central axis between a shielding position, in which the shield member blocks exposure of the substrate to the process energy source, to an exposing position, in which the shutter opening is positioned to expose the substrate to the process energy source. Unfortunately, the shape of the shutter opening of these prior art shutter assemblies prevents uniform exposure of the substrate to the process energy source resulting in non-uniform material depositions.
The present invention relates to a shutter assembly for use in a thin-film processing system that includes a shutter opening having an optimized shape to promote uniform exposure of the substrate to the process energy source. The shutter assembly includes a shield member in which the shutter opening is formed. The shutter opening is defined by sides which are oriented along radial lines of a central axis. The present invention is further directed to a thin-film processing system that includes the above-described shutter assembly.
Other features and benefits that characterize embodiments of the present invention will be apparent upon reading the following detailed description and review of the associated drawings.